Hi!
This is my question:
Does anybody knows the effects that looking at the CD-Player's lasser ray produces in a human being?
That's all!

I'm going to try it. Wait a minute.

depending on how powerful it is it can do great damage to your eye by aiming a laser directly into your eye. And yes, the laser beam itself can be considered invisible, since the light is 'coherent.' Basically what that means is, unless something interrupts the beam the light is travelling more or less in only one direction. That is why they use smoke or fog at a laser show or a concert, the smoke/fog scatters the light and allows you to see the beam itself rather than just the light as it hits a surface like a wall or ceiling. If you take a laser pointer and point it at the wall you can see the spot on the wall quite easily, but you probably do not see any beam travelling from the pointer on the way to the wall. If you take out your fog machine (everyone has a fog machine, right?) and turn that on then point the laser pointer at the wall you would be able to see the beam then, because the fog scatters some of the light and causes the beam to become visible to your eye.

<edit> oh, and the laser in a cd player usually should not be visible under any circumstances, because it is supposed to be an infrared laser which will be just beyond the capability of the human eye to perceive, but it could still damage your eye if it were of sufficient power. (and I'm not sure exactly how much power would be sufficient to cause damage, or how much exposure would be required, etc)

Ribs... Aching... Must... listen... to... Xing... mp3's...

Except for the vicous ringing in my ears I'm fine now. I don't know what I'll do if this guy hangs around...

The problem with laser and eyes is that a laser, unless it passed a lens before is strictly parallel. If the eye is focussed far away, all the energy of the laser is bundled in a very small spot on the retina. So even if the energy of the laser is low, it can produce enough heat on this very small spot do damage retina tissue. This is also the case for infrared and uv light near to the visible spectrum that can pass the eye's lens.
The question for CD players is: Is the laser that can reach your eye sent through a lens before leaving the device or is it parallel? I don't know - maybe someone else?

According to all docs and webpages I've read, the laser is not parallel. It is focused on the CD surface. You can easily see the convex lens.
In addition, it's a class 1 laser, so it shouldn't be very dangerous.

Even if a laser is not within the visible spectrum of what a person has the ability to perceive, it can still damage your retinas quite easily--in fact it is those wavelengths out of the visual-spectrum most likely to do damage. With optical disc players, the laser is only a few mW (5-7mW for example), but direct exposure could damage your eyes. Older models in particular can vary in power. If you are servicing a player, you would be wise to not operate it without at least a disc covering the laser.

When I tore my retina from a trama, the two options I had were either laser or cryo to weld a "patch". In my case cryo was choosen due to the location of the injury (the angle was barely in range for laser). Lasers are also used in newer procedures for corrective eye surgury, although they are greater power than what's found in the common CD player.

Yes, but as the beam passes through a convex lens, the flux per unit of surface decreases in 1/r2 from the focus. According to a friend who made a thesis on non linear optics, CD Player lasers are harmless.

> unless it passed a lens before is strictly parallel

Over very short distances, yes (but that depends to what degree of precision you define "parallel"). Laser beams always diverge...despite corrective optics. A 1/4" diam beam shot at the moon will be miles wide by the time it hits the surface. To (possibly) damage your eye, you would have to put your cornea right on the laser lense (the focal point is like < 5mm from the lense). On top of this...the laser is turned off if it's not playing a CD.

xen-uno